The purpose of the study is to compare, in patients with AIDS and CMV retinitis, the efficacy and safety of two CMV retinitis treatment regimens that do not require the use of a central venous catheter. The two treatments are: 1) ganciclovir intraocular device plus oral ganciclovir and 2) intravenous cidofovir. The primary objective of the trial is to compare the newest CMV retinitis drug, cidofovir, to a commonly used treatment regimen, the ganciclovir intraocular device plus oral ganciclovir, with respect to efficacy in preventing vision loss. A secondary objective is to compare a treatment regimen that incorporates highly active local therapy (the ganciclovir device) with treatment regimens that do not.